Henry dreyfus



UNITED STATES PATENT OFFICE COLORATION F TEXTILE AND OTHER MATERIALS Henry Dreyfus, London, and'Robert Wighton Moncrieil', Spondon, near Derby, England, assign'ors to .Celanese Corporation of America, a corporation of Delaware No Drawing. Application July 29, 1937, Serial No. 156,312. In Great Britain August 13, 1936 0 Claims. (01. 836) This invention relates to the coloring with vat boiling below about 120 C.,'e. g. petrol (gasodyestufis of textile and other materials, more parline) ticularly such as are made of cellulose acetate or (b) Aromatic hydrocarbons, for example benother cellulose ester or ether. zene, toluene, xylene and the like; Vat dyestuffs are usually applied to textile ma- (c) Haiogenated hydrocarbons, for example 6 terial's in the form of aqueous solutions of salts carbon tetrachloride,perchlorethylene, and diof their leuco compounds, the latter being reducor tri-chlorethylene; tion products of the vat dyestufl. After the tex- (d) Alcohols, for example methyl orethyl altile material has taken up orbeen impregnated cohol, no O-D PY eleOhOl e butyi 10 with the leuco compound, the material is subalcohol;

jected to oxidation, usually atmospheric oxlda- (e) Esters, for example ethyl acetate, protion, so as to convert the leuco compound on the. pylor isopropyl-acetate or other volatile esters material back to the original vat dyestufl. having boiling points below about 150 C.

According to the present invention leuco com- Mixtures of organic bases and/0r mixtures of I pounds of vat dyestuffs are incorporated in celneutral organic liquids can be utilised if desired. 15 lulose acetate or other cellulose ester or ether tex- The organic base or the liquid medium contiles by applying them to the textiles in an organic taining it may conta n small amounts of water. liquid medium comprising an organic base. Such It is to be understood, however, that the major a dye liquid may, for instance, be obtained by Po on of the liquid med preferably Q o dissolving a vat dyestufi in an organic base such or more, is organic.

as pyridine, reducing the dyestun' with zinc Certain combinations of organic base and formaldehyde sulphoxylate or other suitable reneutral organic liquid are of particular advantage. ducing agent, and then diluting with an organic Thus, trogen u bases in Which nitrogen forms liquid such as petrol. The leuco compounds partoi a ring may with advantage be used in conafter incorporation in the materials can be conjunction with a hydrocarbon diluent. For exverted into coloring matter by oxidation to the ample, pyridine may be used in conjunction with parent vatdyestutl'. petrol (gasoline), and quinoline in conjunction Various primary, secondary or tertiary organic with xylene. bases may be used as a constituent of the liquid The liquid medium. may be one which has a medium according to the invention. As examples swelling action on the cellulose acetate or other 80 may be mentioned aliphatic amines or other cellulose. ester or ether to be colored. This is amines containing an amino group which is not Pa y relive-11158860115 whenv applyin v directly attached to an aromatic nucleus, for indye liqui s to running three-d5 when pp y stance butylamine, amylamine, or other lower th y mechanical impregnation methods 8 alkylamine, cyclohexylamine, N-dimethyl-cyclopp d to ods in w h t e red et dye- 86 hexylamine, or other hydroaromatic amine, sum s a s rbed fr m th dy qu y t mono-, dior tri-benzylamine, dimethyl-benzylteriel- To s endthe major c mp n nt of t amine, or other aralkylamines, dimpthyl-aniline liquid medium may be one which has the desired or like aromatic amine Quaternary ammonium swelling action on the material. Again, there compounds, e. g., trimethyl-benzyl-ammonium may employed a mixture or liquid which is a hydroxide, may be used if desired. Again, bases strong swelling agent or even a solvent for the m which nitrogen forms part a ring maybe material to be colored, with a liquid of substans d, 1 mun tially no swelling power such as petrol or carbon u e or example pyridine alkyl py tetrachloride. Mention may be made, for inqumonne' or such. piperi' stance, of mixtures of petrol or carbon tetra- The. liquid medium preferably comprises the 2:33.2 with i'wpmpyl alcohql acetone or ethyl organic base in compartively small proportion, dye nqmds'may be prepared m various for example 5 to 15%,the base being diluted-with ya A particularly convenient thod 1 to 5b a neutral organic liq i p ef a y n of reduce the parent vat dystufl' inthe presence or paratively low boiling point, e. g. below about 12 the organic base. For this purpose zinc formalde- C. to 15050. I hyde sulphoxylat'e has been found a particularly As examples of suitable neutraborganic liquids convenient reducing agent. Other reducing may be mentioned the following: agents may be employed, however, for example (a) Aliphatic hydrocarbons, particularly those zinc or other reducing metal, or sulphuretted u hydrogen. The presence of a small amount of water frequently facilitates the reduction, especially when zinc or other reducing metal is being employed. The presence of a small proportion of a metal more electropositive than the reducing metal is often advantageous, particularly when water is present. For example, when using zinc a little copper may be added, conveniently as an aqueous solution of a copper salt. It is usually preferable to eiifect the reduction of the vat dyestuff while dissolved or suspended in the organic base alone or in the organic base only slightly diluted with neutral organic liquid.

Another method of preparing the dye liquids is to prepare the free leuco compound of the vat dyestuff, for example by acidification of an alkaline vat, and then to dry this free leuco compound and mix it with the organic base before or after addition of any neutral organic liquid to be employed. If desired dehydration of the precipitated leuco compound may be effected by boiling with an organic liquid which forms with water an azeotropic mixture of minimum boiling point. Advantageously the organic liquid so employed is one which is suitable as a constituent of the dye liquid. Thus wet precipitated free leuco compound may be boiled with benzene so as to distil off water as an azeotropic mixture with the benzene, leaving the free leuco compound in the excess benzene. This suspension may then be mixed with the requisite amount of organic base, with or without any further neutral organic liquid that may be necessary. The preparation of the free leuco compound and the dye l quid containing the organic base should,

of course, be carried out under conditions such that no substantial oxidation of the leuco compound to the vat dyestufi occurs. If desired, a reducing agent may be present during a part or the whole of the operations in order to ensure that the vat dyestufi is maintained in the reduced state.

The dve liquids are conveniently applied at temperatures as' high as can be used without damaging the material to be colored. For exan' ple'when coloring cellulose acetate using dye liqu ds containing a substantial proportion of petrol or carbon tetrachloride, the liquid may be employed at the boil.

The cellulose-acetate or other cellulose-ester be circulated through bobbins or other packages of cellulose-acetate yarn, rolls of fabric, or the like. and allowed to absorb the reduced vat dyestuff. The latter is then converted again to the original vat dyestufi on the material by a suitable oxidation process.

The dye liquids may, however, be used in other ways for the incorporation of the leuco vat dyestuif in cellulose ester orv ether materials. For example, threads may be run through the liquids. Again, padding, printing or other .methods of mechanical impregnation may be employed if de sired. For instance, textile material may be treated with the dye liquid in the manner and with the apparatusdescribed in United States applications S. Nos. 124,138, filed February 4, 1937; 123,102, filed January 30, 1937, and 124,139, filed February 4, 1937. As indicated above, it is of advantage when applying the dye liquids to ex amples 2 running threads or using methods of mechanical impregnation, to usea liquid medium which has a swelling action on the cellulose acetate or other cellulose ester, or cellulose ether, to be colored.

Various vat dyestuffs may be utilised when dyeing by the new process; special mention may be -e. g., benzoyl amino anthraquinones such as 1:4-

and 1:5-di(benzoylamino) -anthraquinones.

After incorporating reduced vat dyestuffs in cellulose acetate (or other cellulose-ester or cellulose-ether textile materials), the latter may be subject to any treatment necessary to convert the reduced vat dyestuif to the parent vat dyestuff. Air oxidation with or without a mild alkaline scour is usually sufllcient. If desired a special oxidation treatment may be applied, for example treatment in a weakly alkaline bath containing hydrogen peroxide, sodium perborate or the like.

The new process is of special value for the coloration of cellulose acetate or other cellulose esters or ethers. As examples of such other esters or ethers may be mentioned cellulose formatefl.

propionate or butyrate, and methyl, ethyl and:- benzyl cellulose. The invention is also applicable in the treatment of esterified cellulose-derivative materials, e. g. textile materials of an organic derivative of cellulose which have been esteri-- larly animal fibres-such as natural silk or wool.

If desired textile materials containing cellulose-ester or -ether filaments which contain titanium dioxide, carbon black or other pigments may be colored by. the new process. For example, cellulose-acetate yarn of low lustre, owing to the presence therein of titanium dioxide, may be colored. 'Again, a yarn of cellulose-acetate filaments having a grey color due to the presence of carbon black therein may be topped by the new process.

The new process, while of special value in connection with the coloration of textile materials, may be used for the coloring of other materials having one dimension small, e. gqfilms 0r foils of cellulose acetate or other cellulose ester or ether;

The invention is illustrated by the following Example 1 1 kilogram'of Ciba Blue 23 (color Index No.

1183) is dissolved in 10 litres of pyridine, 2 kilo,- grams of zincformaldehyde sulphoxylate added, and the solution diluted with 100 litres of petrol (gasoline) containing 1 kilogram of zinc tormaldehyde sulphoxylate. Cellulose acetate yarn is immersed in the resultant yellow solution for one hour at 80 C., and is then washed in cold petrol and dried in the air. The material is thus dyed a blue shade. If desired, the material may be given a short treatment with a 1 gram per litre soap solution containing hydrogen peroxide after the washing and drying.

Example 2 1 kilogram of Ciba Red G (Color Index N 1226) is dissolved in 10 litres of pyridine, 2 kilograms of zinc formaldehydesulphoxyiate added, and the solution diluted with 100 litres oi petrol (gasoline) containing 1 kilogram sodium tormaldehyde sulphoxylate. Cellulose acetate silk is treated for one hour at 80 C. in the resultant solution, washed with petrol, dried and given a short treatment with a 1 gram per litre soap solution containing hydrogen peroxide. A pink dyeing of good depth and iastness is obtained.

Having described our invention. what we desire to secure by Letters Patent is:

1. Process for the coloration of materials of an organic derivative of cellulose, which comprises forming a dye liquid by dissolving a vat dyestui! in an organic base, reducing said vat dyestul! in the substantial absence of water to form a leuco compound and diluting the resulting composition with a neutral organic liquid, applying the dye liquid thus formed to the materials, and therealter oxidizing the leuco compound to the vat 3. Process for the coloration of materials oi! an organic derivative of cellulose, which comprises forming a dye liquid by dissolving a vat dyostufl in a nitrogenous base in which the nitrogen forms part of a ring, reducing said vat dyestufl in the substantial absence 0! water to form a leuco compound and diluting the resulting composition with a neutral organic liquid, applying the dye liquid thus formed to the materials, and thereafter oxidizing the leuco compound to the vat dyestufl on the material.

4. Process for the coloration of materials of cellulose acetate, which comprises iorming a dye liquid by dissolving a vat dyestufl in a nitrogenous base in which the nitrogen forms part of a ring, reducing said vat dyestufi in the substantial absence of water to form a leuco compound and diluting the resulting composition with a neutrol organic liquid, applying the dye liquid thus formed to the materials, and thereafter oxidizing the leuco compound to the vat dyestufl on the material.

5. Process for the coloration of materials of an organic derivative or.cellulose, which comprises forming a dye liquid by dissolving a vat dyestufl in pyridine, reducing said vat dyestufl in the substantial absence of water to form a leuco compound and diluting the resulting composition with a neutral organic liquid, applying the dye liquid thus formed to the materials, and thereafter oxidizing the leuco compound to the vat dyestufl' on the material.

6. Process for the coloration of materials oi cellulose acetate, which comprises forming a dye liquid by dissolving a vat dyestufi in pyridine, reducing said vat dyestufl in the substantial absence of water to form a leuco compound and diluting the resulting composition with a hydrocarbon liquid, applying the dye liquid thus formed to the materials. and thereafter oxidizing the leuco compound to the vat dyestufi on the material.

RY DREYFUS. ROBERT WIGHTON MONCRIEFF.

CERTIFI GATE 0? CORRECTION.

-Patent No. a, 182,'96 December l2, 19 9,

, HENRY DREYFUS,-ET AL.

It, is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, second column, line 25, for the word "subject" read subjected; line 73, 'for "1185" read 118b,; page 5, second column, line 18, claim for "neutrol" read neutral; and that .the said-Letters Patent should 'be read with this correction-therein that the same may conform to the record of the case in the Patent Office.

Signed'and sealed this 25rd day of January, A, n. 1910.

Henry Van Arsdale,

(Seal) Acting Commissioner of Patents. 

